Grate-bar



J. D. MGKINNON. GRATB BAR.

Patented July 7, 1885.

(No Model.)

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lhnrrnn S 'ra rns JOHN D. MGKINNOX. OF BAY GITY, MICHIGAN.

G RATE-BAR.

SEEQEFECA'IION forming part of Letters Patent No. 321,442, dated July 7,1885.

Application filed May 28, 1885. (No model.)

To all whom it may concern..-

Be it known that l, J OHN D. MOKINNON, a citizen of the United States, residing at Bay City, in the county of Bay and State of Michigan, have invented certain new and useful Improvements in GrateBars; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it apperlains to make and use the same, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification.

My invention relates to improvements in grate-bars, such as are adapted for use in sawdust and slab burning furnaces, and all furnaces using fine fuel; and it consists in the construction and arrangement of a grate-bar, as I shall hereinafter more fully describe and claim.

The objects of my invention are to arrange a gratebar to give a better and more equal draft throughout all its parts, to prevent the clogging up of the draft-holes and provide for a more equal expansion and contraction of the bar, to prevent warping and twisting from the heat, besides making a lighter and more durable grate-bar. I accomplish these objects by means of the mechanism illustrated in the accompanying drawings, in which similarletters refer to similar parts.

Figure l is a detached 'view of a portion of the gratebar in common use. Fig. 2 is a top or plan View of my improved bar. Fig. 3 is a longitudinal vertical section of the same. Fig. l is a transverse vertical section at m m. Fig. 5 is the same at 3 y.

(1. represents a gratebar, the fire-surface of which is provided with diagonal corrugations b, which allow a ventilation or draft of air to pass beneath aslab or any fuel having a flat surface lying upon the grate,and gives the piece a chance to burn, the draft-holes a being lo cated in the channels (7, giving a free admission and circulation of air beneath the fuel. A longitudinal slot, It, is cut between each two alternate holes, a, so that in no place in the bar will the iron continue solid entirely across the bar, except just at the ends, and by this means a more perfect ventilation of the fire is secured, as the holes a, being located in the channels (2, are often filled with fine fuel, such as sawdust or ground bark, the tendency of which is to roll into and fill up a round hole; but the slot h, breaking the circle of the hole 0, prevents the clogging, and being cut through the raised portions b, they admit the air to the thinner portions of fine fuel, and the combustion goes on freely; and the bar being cut into 6 by the holes and slots, as shown in Fig. 2, expansion and contraction of the metal can take place with great freedom and ease, and the liability to warp and twist is avoided. The under side of the bar is braced and stiffened by the longitudinal ribs '5, which extend to and some What beyond the ends of the bar, and are partially cut away on their under edges to form a restingsurface, which lies upon the supports Z and m, the support I being secured to the the front and the support is secured to the fire-wall at the rear. The ends of the ribs iand the bar a are cut away to a considerable angle above the supports Z and m, leaving the open spaces a at the ends of the bar, so that the air is ad- 7 5 mitted between the ribs 1'- over the rests Z and m, and through the spaces a to the fuel at the ends of the grate, causing more perfect combustion to take place, and giving more fire-surface to the grate than with the bars in common use, as shown in Fig. l, the end of which is solid, so that no air is admitted to the fuel at the end thereof.

hat I claim as my invention,and desire to secure by Letters Patent, is-

1. In a grate-bar, the combination of the bar a, the diagonal corrugations b on the firesurface of the said bar, the longitudinal braceribs 23 beneath the bar, and the draft-holes 0 through the bar, with the longitudinal slots 0 h, cut through the said bar, between and joining the two alternate holes 0, substantially as and for the purpose set forth.

2. A grate-bar having the corrugations b on its fire'surface, and the holes 0 and slots 5 it through its body, in combination with the stiffening-ribs i, extending the whole length of and beyond the ends of the said bar, and arranged at their ends to form a bearing-surface for supporting the bar, and with the open space a between the said ribs and at the end of the said bar, substantially as and for the purpose described.

In testimony whereof I affix my signature in presence of two witnesses.

Witnesses: JOHN D. MCKINNON.

J. E. THOMAS, F. H. BURTON. 

